RATIONALE: Estrogen can cause the growth of breast cancer cells. Hormone therapy using letrozole +/- goserelin (the latter for pre-menopausal women only) may fight breast cancer by lowering the amount of estrogen the body makes. OSI-906 and erlotinib hydrochloride may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. It is not yet known whether hormone therapy and OSI-906 are more effective when given with or without erlotinib hydrochloride in treating hormone-sensitive metastatic breast cancer.